Process and apparatus for bituminous sand treatment



April 18, 1961 A. E. KELLEY 2,980,600

PROCESS AND APPARATUS FOR BITUMINOUS SAND TREATMENT Filed July 19, 19572 Sheets-Sheet 1 A/mm ow' 111/0 1 250 lira-1.

Ava/me April 18, 1961 A. E. KELLEY 2,980,600

PROCESS AND APPARATUS FOR BITUMINOUS SAND TREATMENT Filed July 19, 19572 Sheets-Sheet 2 I! 1 main/- [la 40 terial near the earths surface. ofcrude petroleum due to. production and depletion of PROCESS ANDAPPARATUS FOR BITUMINOUS SAND TREATMENT Arnold E. Kelley, Fullerton,Calif., assignor to Union Oil Company of California, Los Angeles,Calif., a corporation of California Filed July 19, 1957, Ser. No.673,066

Claims; Cl. 208-11) This invention relates to the recovery ofhydrocarbons from hydrocarbon-containing solids such as tar sand,oilsoaked diatomite, and the like. This invention particularly relatesto an improved process and apparatus for treating such materials atrelatively low temperatures utilizing particularly efficient washing andseparation steps to effect a substantially complete recovery of thehydrocarbon material present.

Extensive deposits of tar sands or bituminous sands are known to existat widely separated places in the world. These materials are essentiallysilicious materials, such as sands, loosely agglomerated sandstones, ordiatomaceous earth, saturated with relatively heavy or viscoushydrocarbon materials resembling low gravity crude petroleum. They existnear the surface of the earth and are generally discovered throughlocation of their outcroppings. Extensive deposits of such materialshave been discovered in the Athabaska region of Northern Alberta,Canada, in the Uinta Basin near Vernal in Northeastern Utah, and in theSanta Maria area of Southern California about 130 miles northwest of LosAngeles. In this latter area extensive deposits are found in the SisquocRiver Valley, near Casmalia, and elsewhere.

Surveys of these deposits have reavealed that they contain tremendousquantities of hydrocarbon materials very similar to low gravity crudepetroleum, and individual deposits have been estimatedto contain on theorder of 60 to 70 million barrels of tar sand oil. EX- tensive recoveryof these oils has not been achieved, primarily because of the expenseinrelation to crude petroleum in spite of the fact of the accessibilityof the ma- However with rising costs known petroleum reserves, anefficient and economical process and apparatus for, the treatment ofsuch bituminous sands has become highly desirable.

The principal disadvantage in previous processes lies the extensiverequirement of reagent and in the difficulty of separating the veryheavy oil from the sand or other solid grains after the pulping ortreating step. The present invention successfully overcomes thesedisadvantages through the utilization of a particularly eflicient methodof treating the pulped material to effect sand separation while avoidingoil rewetting.

In the following description the phrases bituminous sand or tar sand areused to refer generally to all granular solid bituminous orpetroliferous materials soaked with a usually highly viscous liquid orsemiliquid hydrocarbonaceous material, although it specifically refersto a characteristic type of bituminous solid consisting of discreteparticles of sand bound together by a continuous viscous hydrocarbon oilphase. This terminology is used for the sake of simplicity ofdescription, and it should be understood that the process and apparatusherein described may be applied to other solids similarly containing abituminous or viscous hydrocarbonaceous coating.

2 ,980,600 Patent ed Apr. 196].

The present invention is directed to a low temperature process using awarm aqueous solution of a special alkali metal silicate, with orwithout other reagents, and a moderately heavy hydrocarbon diluent toseparate the heavy oil from the bituminous sands, and in which processspecial procedures and apparatus are used in handling the effluent fromthe mixing step in which these materials are heated and agitated withone another to'etfectthe separation of the heavy oil from the sand.

It is a primary object of th s invention to provide an improved processforl.the separation and. recovery. of heavy oil from bituminous solidssuch as tar sand-and the like.

It is a specific object of thisinvention to treat and recoverhydrocarbon oil from tar sand by pulping it with a mixture of aqueousalkali metal silicate with or without other reagents and a hydrocarbonsolvent at slightly elevated temperatures to separate the oil from thesand.

It is a particular object of this invention to provide in this process apreliminary separation step applied to the pulp flowing from a pulper ormixer to produce sub.- stantially clean sand and a mixture of theaqueous chemical and the oil phases together with the step of treatingthe sand to free from it all of the mechanically occluded oil. 1 1 1 Itis a further object of this invention to. provide an improved apparatusadapted to effectthe foregoing objects.

Other objectsand advantages of this invention will become apparent tothose skilled in the art asth'e .description and illustration thereofproceed.

Briefly, the present invention comprises, an initial step of feeding thesand in chunks continuously through a feed hopper which controls therate of flow to a mixer. Here it is mixed and pulped with an aqueoussodium silicate solution and a hydrocarbon solvent at a slightlyelevated temperature. This mixing continues for a period of betweenabout 0.2 and about 2.0 hours and at a temperature of between about F.and about 250 F. Preferably this mixer is of the rotary kiln typeprovided with internal baffles and conveyor flights so as to control theresidence time of the material in the mixer. This treatment reduces thetar sand chunks to a heavy slurry or pulp of sand,water, and oil. v c

The efiluent from the mixer or pulper is a slurry or pulp of treatedsand, aqueous chemical solution, anda hydrocarbon phase including theseparated bitumen and the relatively light diluent oil. This slurry orpulp is discharged immediately to a primary separation Zone in which avery rapid separation of the treated solids is effected. This leaves astream of fluid including the hydrocarbon and aqueous phases. Sincethere is a considerable quantity of sand present at all times in thisprocessing step, it is essential that some slight sand agitation beeffected in order to liberate residual oil droplets which are trapped inthe downwardly progressing sand during the dropout of the sand grainsfrom the fluid phases. The sand is discharged at the bottom of theprimary separator into a washer-drier in which a considerable quantityof the water present in the sand stream is recovered for recirculation.If desired, makeup water to the process may be added at this point torecover residual silicate solution from the sand as well.

From the top of the primary separator are discharged the aqueous andhydrocrabon phases substantially free of sand grains but containingvariable amounts of very fine solids such as silt and clay. In theseparator thickener zone, to which, these phases flow, a substantiallycomplete removal of these silt-like solids is effected from the aqueousphase and a clean water stream is produced forrecirculation. Aconcentrated wet oil phase is dis- .1- charged therefrom into a settlingzone such as .a wash tank in which the material is allowed to stand forperiods of between about and 25 hours to produce essentially .waterandsilt-free oil, the oilbeing a dilute mixture of hydrocarbon diluentand the relatively heavy hydrocarbon or bitumenseparated from the sandinthe process. This'oil phase is at some point treated as'bydistillationto recover the diluent oil for recirculation to the pulper.An aqueous phase containing the silt is recirculated from the settlerback to the thickener zone to produce clear water. From the thickenerzone is ,removed a concentrated slurry of silt and water which isdischarged to outdoor settling basins.

' As illustrated by. the following examples and as described.herein,'the specificsteps taken in the separator and settling zones toprevent contact of the sand with separated oil and to recovermechanically trapped oil from the settling. sand have been found to beextremely important in the successful recovery of up to 99.9% of theseheavy oils and in the production of clean sand containing less than0.10% of the original oil.

The process of the present invention is best described and illustratedby reference to the accompanying drawings in which:

.Figurel is a schematic flow diagram showing portions :of theapparatusin elevation view,

Figure 2 is an elevation view in cross section of the primary separationzone of this invention,

Figure 3 is an enlarged detail view of the top of the primary separator,and

Figure 4 graphically illustrates the efiect of the adjustment of .theheight of the various oil outlet lines.

Referring now more particularly to Figure 1, the es sentialequipmentelements employed in the process and apparatus of the present inventioninclude pulper or :mixer 10, primary separator 12, sand washer and drier14, thickener'16, and product settler 18. The subsequent discussion ofthe invention in connection with Figure 1 will be conducted .as vatypical example of the process and apparatus of this invention appliedto the treatment of Sisquoc bituminous sand at a rate .of approximately200 tons per day. Althoughthe tar sand 'may contain between 20 and 40gallons of oil per ton and have a gravity from 2 to API, a typicalbituminous sand contains about 30 gallons per .ton of 4 API gravitybitumen.

The freshly mined bituminous sand is vintroducedlinto upulper 10 bymeans of conveyor 20 at airate of 200 =t./d. (tons per day) controlledby solids feeder.21. A light coker gas-oil as diluent oil is introducedat a rate of 191 b./d. (barrels per day) and a temperature of .180'F.through line 22 at a rate controlled by valve 24.

.Alsointroduced into the pulper is the. aqueous alkali metal silicatesolution with or without other reagent which flows through line 26 at arate of 286 .b./d. controlled by valve 28. This material is maintainedat a temperature of about 180 F. by means of heater or exchanger 30. Tomaintain a pulper temperature of about 180 F. within pulper 10, steam atthe rate of 482 pounds 'per hour is also introduced through line 32 at arate controlled by valve 34.

The relative rates at which the foregoing ingredients :are introducedinto pulping zone 10 are specific to one typical operation. In generalhowever they are preferably maintained within certain limits in order toefiect the most rapid and etficient liberation of the'bituminousmaterial from the sand or other solid grains. Pursuant to this thediluent hydrocarbon rate is that sufficient to produce an oil phasehaving an API gravity above 10.0,

'and is preferably maintained between limits .of about 0.1 and about 2.5b./t. (barrels per ton) of raw bitumen sand feed. The aqueous silicatesolution is introducedat arate maintained between about 0.75 and'about5.0 b./t. of raw sand feed,'and'preferablybetween about 1.0 and 1.5b./t. This aqueous solution contains between about 0.5 and 20, andpreferably between about 0.75 and about 10.0 pounds of an aqueous sodiumsilicate concentrate per barrel. This concentrate is a 34% by weightaqueous solution and is a special material marketed commercially underthe name Silicate 120." It has a Na O to SiO ratio of about 0.55 mol permol. Other high basicity sodium silicates may be substituted providedthis ratio is above about 0.4 and preferably greater than about 0.5. Thecommercial water glass of commerce isnotsatisfactory since it has aratio of about 0.25.

The pulping temperature must be maintained higher than about F. andpreferably is maintained above F., although it ordinarily should not runabove about 250 F. The operation ofthe pulping zone is controlledrelative to the set rate and the size of the pulper so that the rawbituminous sand is subjected to the action of steam, the aqueoussilicate, and the hydrocarbon diluent within the pulping zone for aperiod of between about 0.1 and 2.0.hours. Under the conditions givenpreviously a pulping time of about 0.25 hour will liberate substantiallyall of the bitumen from the sand and produce a spent sand containinglessthan about 3.0 pounds of hydrocarbon per ton.

The discharge end of pulping zone 10 is provided with trash screen 36 bymeans of which rocks and nondisaggregated lumps of tar sand aredischarged from theas short as possible and providing for the immediatetransfer of the pulp from the pulper into the primary separator.Preferably line 40 is an inclined pipe having a slope of not less than60 relative to the horizontal. The interior of primary separation zone12' is provided with a plurality of bafiies 42 over which the settlingsand progresses in sequence to provide the gentle agitation necessary toliberate mechanically trapped oil drops from the sand stream. Additionalagitation is provided by introducing 'fluid hereinafter more fullydescribed into the bottom of primary separation zone 12 through line 44at a rate controlled by valve 46.

From the bottom of primary separation zone 12 .th treated sanddischarges through line 43 at a rate controlled by valve 50, which maybe a density valve responsive to the density of the sand-water slurrycollecting in the bottom of primary separation zone 12. In any event,the sanddischarges at a rate of 172 t./d. .1nt o washer 14 along with193 t./d. of water. Th'esand is picked up and conveyed upwardly by meansof conveyor 52 whereby agravity separation of theaqueous phase isprovided. Preferably, part or all of the makeup water to'the system isintroduced by means of l1ne 54 controlled by valve 56 as wash water tothe washer-drier. The clean,

oil-free sand is discharged from washer-drier 14 by means of line 58 andis conveyed to a suitable disposal point. The aqueous phase removed withthe sand from the primary separation zone 12 is'separated fromwasher-drier 14 through line 60'and is discharged into the central well62 of thickening zone 16. This stream flows at about 160 F; at a rate ofabout 1168 b./d., containing about 5 't./d. of sand and 1 b./d. of oil.

The annular-volume outside well 62 is sizcd.to..-give a water residencetime of about 6 hours during which time substantially all ,of' the siltsettles from the aqueous phase. Rake arms 64 are provided with rakesinclined at such an angle so that rotation of the rakes move the settledsilt as a thickened sludge: radially inward toward silt outlet 70. Thethickened silt is removed through line 70 at a rate controlled by valve72, the silt concentrate containing about 87 b./d. of water and 15.0t./d. of solids.

The clear water effluent is removed from'collector 74 surrounding theupper periphery of thickener 16 by. means of line 76 at a rate of 1821b./d. This material actually constitutes the aqueous silicate solution;to which makeup aqueous silicate concentrate is introduced .by means ofline 78 at a rate of 2.5 gallons per hour-icontrolled by valve 80. Freshwater is introduced by means of line 82 at a rate of about 355 b./d.controlled byvalve 84. This may, if desired, flow into the clearaqueous: stream in line 76. As previously indicated this is prefer ablyemployed, wholly or in part, as wash water'for the spent sand and isintroduced through line 54 previously described. The total aqueousstream from thickener 16 continues through heat exchanger 30. It isheated to about 180 F. and is introduced into pulping 'zone through line'26 as previously stated.

The overflow of the wet oil phase from primary separator zone 12 passesthrough line 86 into central well 62 of thickener 16. This stream flowsat a rate of about 1081 b./d. and includes 754 b./d. of water, 327 b./d.of oil, and 12 t./d. of silt and sand. The temperature of the stream isabout 175 F.

Also introduced into the central well 62 at a tempera ture of about 155F. is a relatively small stream of water from the bottom of settlingzone 18. This passes through line 88 into central well 62 and contains67 b./ d. of water, 1 b./d. of oil, and a trace of silt and sand.

In central well 62 broken line 90 indicates the approximate position ofthe oil emulsion-aqueous phase interface. This is maintained at adistance about two-thirds of the way down in the central well. Theaqueous streams flowing through lines 60 and 88 from washer-drier 14 andsettling zone 18 respectively are introduced below this level becausethey contain only slight quantities of oil. The primary separatorefliuent flowing through line 86 and containing about 30% by volume ofoil is introduced above level 90 into the supernatant phase consistingof separated oil' and possibly a layer of oil water emulsion, Preferablythe interface wet oil phase from weir box 92 or other removal means iscontrolled so as to maintain a substantially constant position of theinterface.

the wet oil stream is removed from weir box 92 through line 94 at a rateof 409 b./d. controlled by valve 96 or other means. The temperature ofthis stream is approximately 168 F., and it contains 328 b./d. of oil,81 b./d. of Water, and 2 t./d. of sand.

This wet oil stream is discharged into separator zone 18 by means ofdistributor 98 disposed in the lower portion of the settling zone.Heating coil 104 is provided within settling zone 18. Preferably thevolume of settling zone 18 is suflicient to give the wet oil a residencetime of about 12 hours permitting it to separate into dry oil.

and aqueous phases. The separated aqueous phase is removed from thebottom of settling zone 18 through line 88 and contains a trace ofsolids, but is otherwise essentially all Water. The dry oil is removedfrom the top of settling zone 18 by means of take-off weir 100. Thisstream is pumped by means of a pump not shown through line 102 todistillation facilities which may be located at the plant site or at aremote area where it is associated with oil refining facilities'fortreating the recovered oil. This stream flows at a temperature of about153' F. and contains 321 b./d. of oil, '2 b./d."of water 75 which opensupwardly to a point justopposite theup denoted by line 90 is detectedcontinuously and the rate of removal of the supernatant In any event,the residence time for the oil phase is approximately one hour and pulpinlet line 40.

and-0.1 t./d. of solids. The'effiue'nt dry oil. is heated, in exchangermeans 106 and is distilled in distillation ,col-.' umn 108. A strippinggas such as steam is introduced into the bottom of distillationcolumn108 through line 110 at a rate controlled by valve 112. The overheadvapor flowing through line 118 fromstill 108 is condensed in condenser120, part of the condensate is returned through line 122 as reflux, andthe remainder is pumped by means of a pump not shown through line 22into pulping zone 10. The stripped diluent oil-free bitumen is removedthrough line 114 at a rate of 137 b./d. controlled by valve 116. Thisproduct oil has the following properties:

. TABLE 1 v Product oil characteristics Viscosity, SUS at 180 F. $0,200Carbon residue, percent by weight V 16.05

By means of the above described process, bituminous sands are readilytreated to effect better than 96% by volume of bitumen contained thereinat moderate temperatures and pressures and with only slight consumptionof chemicals. The sand discharged from the system contains less than 5pounds per ton of residual-oil,

Referring now more particularly to Figure 2, a vertical cross section ofprimary separation vessel 12 is shown to illustrate the detail of theinternal baffles and oil col lection equipment. Pulp inlet 40 opens intothe upper end of primary separator vessel 12. The sand outlet 48 opensfrom the bottom thereof and is provided with bed of solids and controlsthe rate of solids removal so as to maintain a compact sand bed 128 from2 to 15 inches thick moving downwardly and outwardly across the surfaceof the vertical conical primary baffles 126, 128, and 130, and inwardlyand downwardly across the uppersurface of inverted truncated secondarybafiles 132 and 134. In this way the countercurrent flow of the aqueousphase, described immediately below, -is filtered. through the movingsand bed. This reduces to a minimum the amount of fine solids and siltcarried up and out with the fluid oil and aqueous, phases.

The downwardly moving sand bed receives moderate physical agitation dueto its zig-zag or serpentine path;

' However, to enhance the agitation'and to insure that the downwardlymoving bed of sand is disturbed sufficiently to liberate the occluded ormechanically trapped oil particles, fluid inlet 44 and valve 46 areprovided. The:

fluid so introduced is a recirculated stream of the dilute aqueoussilicate solution. It is introduced at arate sufficient to eifect a netupward flow of the aqueous phase through primary separator 12, and toagitate the moving bed of sand therein. As shown in Figure 2 the'lowerperipheries of the primary and secondary baffles are provided withoutwardly and inwardly projected louvres respectively. The louvredportion does not exceed about 35% of the slant height of the conicalsection of the baffle and thus the silicate solution passes through thelouvres and then transversely through the downwardly moving solids bedsuperimposed above the baffie surface. This serves to agitate and sweepout of the disturbed sand bed small globules of oil and carry themupwardly from the sand bed with the aqueous flow into an area below thenext superjacent baffle.

' As indicated in Figure 2, the primary bafiies, as represented bybaffle 126 for example, is provided with a flat bottom portion 136 and acentral riser portion 138 Itdetect's the presence of a compactpermostlouvre; This-serves to direct-the rising silicate solution anditheliberated oil globules'centrally into-the primarybafile. Due-to the flowarea enlargement'at the outlet of the riser, the liquid velocity israpidly decreasedpermitting-the oil globules to rise slowly to an oilaccumulation just below the apex 138 of the primary hafile; The silicatesolution then progresses radially after separation of theoil' globulesthrough'the louvres 1 40.- and then back through the downwardly movingsand bed to. liberate more oil particles. i

The secondary bafiles, represented by baflle 132for example, are alsoprovided-with a-flat portion-142'and a vertical cylindrical riserportion144. This cylindrical portion also extends to approximately the top ofthe louvres and its .purposeiszthesame, namely to permit separation ofthe oil globules beforethe silicate solution. passes through thenextset'of. louvres. and back into .the sand bed. i

Y The net effect of the baflle structure shown and described aboveis'the' s'equential agitation of thedownwardly moving sand bed by'mean'sof a countercurrent flow of aqueous silicate solution, separation from.the silicatesolution of any .oil globules liberated from the sand, andthen passage of the silicate solution again through the-nextsand bed.These steps are of course repeatedin sequence until the silicatesolutionemerges. from the uppermost end of ,the solids bed.

, From the upper portion of each primary bafllelead primary oil outletlines 150, 152 and 154. Correspondingly, secondary oil outlet'lines 156'and 158 are. pro-, vided at the upperends of secondary baflles 132and134. These lines extend upwardly to a point adjacent. oil and wateroutlet 86 whichzopens from a point near the top of, primary. separatorvessel 12. These oil collection lines areeach provided with -a valve 160for control purposes and to minimize flow surges. The upper end 162 ofeach line is disposed at a point above liquid level 164 which is fixedby the position of oil and water-outlet 86. By proper adjustmentof thedistance of each of the outlet-openings 162 above liquid level 164,the-oil collection lines may be made-to dischargeonly oil at a rate.equal. to the rate that it collects beneath the various baflies, andprevent the-bypassing of the upwardly flowing. silicate solutiontherethrough.

First collection line 150 has a, liquid pressure imposed uponitsentrance. which is equal to the hydrostatic head. of liquid in separatorvessel .12 above the entrance point to liquid level 164, plus thepressure differential: gen-. eratedby the flow of silicate solutionthrough the solids bedaround the uppermostprirnary baflle 126. Themagnitude ofthis differential varies with the silicate ,fiow: rate-andthe thickness of the sand bed above each bafile. Preferably adifferential of at least inches of water is. maintained across each bed.This means then that. theliquid contained in first oil outlet line 150will ordinarily stand in that line to a height above liquid level 164which. is equivalent to this pressure'differential generated by the,liquid flow through the sand bed, since the hydrostatic. head intheseparator vessel will be essentially balanced by that in line 150.This pressure differential maybe. determined by a differential pressureindicator 174, or the, height may be manually adjusted during operationwhile, an ,operatorwatchesits-operation; In either-case, theupper outletend 162 of first oil collection line 150 is adjusted so'as to be ata-distance above the liquid level 164 which. is less than thehydrostatic head expressed in feet or inches of oil phase equivalent tothe pressure-- drop of silicate. flow through the sand bed, and which isgreater than the corresponding equivalent hydrostatic head of theaqueous phase. This adjustment is made: for each of the oil outletilines opening'fromgtheupper end-fromeach of=the primary and secondarybaffles; it, heingsnoted; that" the..- height differences. for"theisucces-i. sively: r lower. outlet? lines]. are successively;greater siricer the pressure difierentials of 'theliquid flow throughthe sand beds are additive a p IThisadjustment and the heightdifierence's are more clearly detailedin F igu'res Sl-and- 4. V a jReferring-now to Figure 3'th'e uppermost section-of primary separatorcolumn. 12 is shown together with oil and waterfoutlet line- 86 and pulpinlet line 40. The first'four successively lower oil outlet lines areshown as lines- 150, 156, 152, and-158. An adjustable sleeve 170,enlarged at its upper end to eliminate liquid level fluctuationsdue tosurging in the line, is provided at the upper end-of; eachofftheseoilcollection lines together with-fadjustmeutmeans-V172 whereby the heightofjeach' oil collection hne above liquid level.164 may be varied. In-Figure; 2 the pressure; differential existing. across the sand bed' frompoints inside primary baflle 126 and above the superjacent sand :bedisindicated by differential pressure indicator 174. This differentialpressure, in pounds. per. square .inch 'for, example, has anequivalenthydrostatic head expressed in inches ot'the oil phaseand alsoan equivalent headwhich maybe expressedin inches of the aqu ous phase.These equivalent heads are of course dependent upon the specific gravityof each of these phases, the inches of head for the aqueous phase beingsmaller than the inches ofjhead for the oil. phase with oil phases ofgravity. greater .than lO API. 7

.According' to the. principles of. the present invention, the distance,at which upper outlet opening 162 of first oil collection line aboveliquid level 164 is equal, r011 and this is adjusted. by means of asleeve, not

shown but equivalent to 170, to a valuein inches which.

is. greater, than 1 the equivalent aqueous. head and lessthantheequiyalent hydrocarbon head. Then for agiven fiowrateof silicatesolution throughv the sand bed generatinga-given differential pressure,the .oil: will. collect uni der primary bafiie.126. and accumulate inoil outlet hue, 150 until sufficient. oil exists in the collection lineto raise the head above outlet opening 162. At this-time only. oilwilljdischargev and. flow from separator-12 through outlet line.86. Ifno oil is collected at this point, the aqueoushead equivalent-totheexisting-differential pres-. sure is. not suflicient 'to cause water to.overflow from outlet 162, since the equivalent aqueous head is less thanh Therefore only-oil, when and if it accumulates in sufficient-amounts,will overflow. No aqueous phase can bypass the sand beds through theoil'collection lines.

Identical considerations apply to each of the succes Siva-4, 5 or'moreioil-collection lines with successivelygreaterheads h h h .etc.

The'nature of the fluid overflowing from a given oil collection line-is-indicated' in Figure-4 in the manner of a phase diagram.Theequivalent liquid head for the;

oil and, aqueous phases are here related to .the total accumulativepressure differential of aqueous silicate flow; throughgthe sand beds.-Theequivalent head of the oil. phase is shown .by curve and theequivalent head for the aqueous phase is-shown by curve 182. If foragiven total effective pressure diflerential the height differential his. set at a value-corresponding to point 184,.th6fl'the aqueousheadequivalent exceeds the height:

differential. and water andany oil accumulating below the correspondingbaffiewill overflow at the outlet of each of'the oil collection lines.This means that aqueous phase flow can bypass the sand beds throughtheoil collection lines to the primary separator outlet. If

the height differential is set at a value corresponding to point 186,there will be no fluid overflow at all since- 75. willsoverflow. .sincezonly: a'zlhyd ostaticjhead; of;;oil in 'the' the downwardly moving sandbed while permitting any separated oil to flow through theselines out ofcontact with the settling sand. I

The primary separator equipment of the presentinvention was applied inthe treatment of Sisquocv bitu-j minous sand as described in connectionwith the preceding Figure 1. The primary separatorcolumnvwas 10 feethigh and 22 inches in diameter and was pro- .vided with conical bafilessubstantially as shown in Figure 2. With a flow of bituminous sand ofabout 172 t./d. downwardly through the separator so as to maintain adense downwardly moving bed through the separator, an upward silicateflow countercurrent to the sand of about 1300 b./d. was maintained. Theheight differential of each of the oil collection lines was adjustedvisually while the nature of the fluid overflowing was observed. Withmore or less steady operation an excessively low height resulted in anexcessive liquid flow, primarily of aqueous silicate solution," from theoutlet of the oil collection line. The height was graduallyincreaseduntil a steady smoothoverfiow of oil resulted. The height differentialsof all of the lines were similarly adjusted. The sand produced from thebottom of the primary separator contained as low as 2 pounds-of residualoil per ton. v p

A particular embodiment of the present invention has been hereinabovedescribed in considerable detail by way of illustration. It should beunderstood that various other modifications and adaptations thereof maybe made by those skilled in this particular art without departing fromthe spirit and scope of this invention as set forth in the appendedclaims.

I claim:

1. In a process for the recovery of hydrocarbon values fromnaturally-occuring hydrocarbonaceous mineral solids which comprisescontacting said solids with an aqueous chemical solution and ahydrocarbon diluent at a moderately elevated temperature for a periodsufiicient to reduce said solids to a homogeneous fiuid pulp, and saidpulp is then treated to separate it into a solids phase, a hydrocarbonphase, and an aqueous phase, the method of effecting said separationtreatment which comprises: (1) introducing said pulp into the upper endof a confined vertically elongated separation zone, said separation zonecomprising within its confines a plurality of vertically spacedhydrocarbon separation zones; (2) allowing the solids components of saidpulp to settle into a substantially compact bed at the upper end of saidseparation zone; (3) allowing said compact bed to descend by gravitythrough said separation zone to the lower end thereof while directingthe path of said descent past said hydrocarbon collection zones andalternatel'y towards the periphery and towards the axis of saidseparation zone, whereby the solids pass downwardly in a sinuous paththrough said separation zone in the form of a continuous compact bedhaving the shape of a vertical sinusoidal envelope; (4) removingessentially hydrocarbon-free solids from the lower end of saidseparation zone; (5) simultaneously introducing an aqueous liquid intothe lower end of said separation zone; (6) passing said aqueous liquidin a continuous stream upwardly through said separation zone and throughsaid hydrocarbon collection zones in a sinuous path which passestransversely across the sinusoidal path of descending compact solidsbed; (7) removing an aqueous phase from the upper end of said separationzone; (8) removing a hydrocarbon phase from each of tact with saidaqueous liquid to a discharge point located a sufficient distance abovethe liquid level in said separation zone that substantially onlyhydrocarbon is discharged at said point; and (10) removing theso-discharged hydrocarbon from the upper end of said separation zone.

2. A process as defined by claim 1 wherein said hydrocarbonaceousmineral solids is tar sand.

3. A process as defined by claim 2 wherein the thickness of saiddownwardly moving compact solids bed is maintained between about 2'andabout 15 inches, and the said aqueous liquid is passed upwardly throughsaid separation zone at such a rate that a pressure diflerential of atleast about 5 inches of water is generated each time the said aqueousliquid passes through said descending solids bed. 7

4. A process as defined by claim 2 wherein the said chemical solutionand said aqueous liquid consist essentially of an aqueous solution ofsodium silicate in which the Na O/SiO ratio is at least above about 0.4.

'5..The process for recovering hydrocarbon values from bituminoussandswhich comprises (1) agitating said sand at a temperature betweenabout F. and about 250 F. with between about 0.1 and 2.5 barrels per tonof a relatively light hydrocarbon oil and with between about 0.75 andabout 5.0 barrels per ton of an aqueous sodium silicate solution for aperiod of time sufficient to form a substantially homogeneous fluidpulp, said sodium silicate solution containing between about 0.5 andabout 20 pounds per barrel of an aqueous sodium silicate concentratewhich contains about 34 percent by weight of a sodium silicate having aNa O/SiO ratio of at least about 0.5; (2) introducing said pulp into theupper end of a confined vertically elongated separation zone; (3)allowing the solid components of said pulp to settle into asubstantially compact bed at the upper end of said separation zone; (4)allowing said compact bed to descend by gravity through saidseparationzone while directing the path of said descent alternately tothe periphery and to the axis of said separation zone a plurality oftimes, whereby the solids pass downwardly in a sinuous path through saidseparation zone in the form of a continuous compact bed having the shapeof a multi-noded vertical sinusoidal envelope having walls between about2 and about 15 inches thick; (5) removing essentially hydrocarbon-treesolids from the lower end of said separation zone; (6) simultaneouslyintroducing aqueous sodium silicate into the lower end of saidseparation zone; (7) passing said aqueous sodium silicate in acontinuous stream upwardly through said separation zone in a sinuouspath which passes transversely through the walls of the aforesaidenvelope of descending solids; (8) removing an aqueous phase from theupper end of said separation zone; (9) collecting a hydrocarbon phase ateach of a plurality of points within said separation zone, each of saidcollection points being located within said envelope of descendingsolids at top of each node of said envelope; (l0) separately passing thehydrocarbon phase collected at each of said collection points in theform of a confined stream out of contact with the descending solids andout of contact with said aqueous sodium silicate to a discharge pointlocated a sufficient distance above the liquid level in said separationzone that substantially only hydrocarbon is discharged at said point;and (11) removing the so-' through its Wall adjacent to its upper endandatsolids outlet opening adjacent its lower end; a pulp Iinlet conduitextending into said vessel adjacent its upper end and terminating Withinsaid vessel at a point below said outlet opening; a plurality of primarybaflles positioned in spaced relationship within said vessels, each ofsaid" primary baffiestaking the form of a hollow cone whose axiscoincides with'that of said vessel, whose apex is directed upwardly,whose lower periphery has a diameter less than the internal diameter ofsaid vessel, and having louvres opening through its wall adjacentthe'lower edge thereof; a plurality of secondary bafiles positioned inspaced relationship within said vessel and alternation with said primarybaffis, each of said secondary bafiies' taking the form of ahollow'inverted truncated conewhose axis coincides 'with that of saidvessel, whose upper peripheral edge is in register with the wall of saidvessel, and having'louvres opening through its wall adjacent the loweredge thereof; a plurality'of first conduit means each of which extendsthrough the wall of one of said primary baffles adjacent the apexthereof and'terminates at a point above said outlet opening; a pluralityof second conduit means each ofwvhich extends from a point adjacentandbelow the upper edge of one of said secondary baflles and terminatesat a point above'said outlet opening; and a liquid inlet conduitextending through the wall of said vessel and terminating within saidvessel at a point below the lowermost of said bafiles.

7.An apparatus as defined by claim 6 wherein the uppermost of saidbaffies is a primary bafile having its apex disposed immediately belowthe opening of said pulp inlet conduit, and the lowermost'of saidbafiies is a primary baffie having its apex disposed immediately above-12; of said-"primarjrbafiies is *provided with anannular plate" havingits outer edge in register with the lower edge offlthe b'afile a'ndanopen-ended cylindrical element extending from the inner edge of saidplate upwardly to a level'adjacent that of the uppermost of the louvresof said-Y primary bafile and each of said secondary baffles isprovidedwith'an annular plate having its. inner edgein' register with the loweredge of the =bafiie and an openended cylindrical elementextendingfromthe outer edgeof said plate'upwardly'to a leveladjacent that of theuppermost of 'thelouvr'es' of. said secondary baffle;-

9. An apparatus as defined by claim 6 wherein means areprovided';for-adjusting the levels atwhich said first and 'se'condconduit nieans terminate above saidoutlet opening. 1 a i 10. An aparatus-a defined Lby claim 9 wherein said level adjusting meanscomprises a vertically movable sleeve disposed. in-li'q'u'id receivingrelationship at" the upper end of each of 's'aid first andsecond'conduit means; a substantial'part of saidsleevehavingia diametersubstantially largerthan that ofi the conduit means'withwhich it isassociated;

v References Cited in the file of-this patent UNITED STATES'PATE'NTSRe.21,72'5'j Harrington Feb. 25,- 1941' 1,497,607" StreppeL, June 10,1924 2,303,717 Arveson Dec. 1, 1942 2,364,453 Layng et'al. Dec. 5, 19442,409,596 7 Simpson etial. -Oct. 15, 1946 2,453,060 Bauer etval. Nov. 2,1948 2,531,365 Simpson et 'al. Nov. 21, 1950 2,825,677 Coulson Mar. 3'-,1958 FOREIGN :PATENTS 563,883 France-e Oct; 5', 1923

1. IN A PROCESS FOR THE RECOVERY OF HYDROCARBON VALUES FROMNATURALLY-OCCURRING HYDROCARBONACEOUS MINERAL SOLIDS WHICH COMPRISESCONTACTING SAID SOLIDS WITH AN AQUEOUS CHEMICAL SOLUTION AND AHYDROCARBON DILUENT AT A MODERATELY ELEVATED TEMPERATURE FOR A PERIODSUFFICIENT TO REDUCE SAID SOLIDS TO A HOMOGENEOUS FLUID PULP, AND SAIDPULP IS THEN TREATED TO SEPARATE IT INTO A SOLIDS PHASE, A HYDROCARBONPHASE, AND AN AQUEOUS PHASE, THE METHOD OF EFFECTING SAID SEPARATIONTREATMENT WHICH COMPRISES: (1) INTRODUCING SAID PULP INTO THE UPPER ENDOF A CONFINED VERTICALLY ELONGATED SEPARATION ZONE, SAID SEPARATION ZONECOMPRISING WITHIN ITS CONFINES A PLURALITY OF VERTICALLY SPACEDHYDROCARBON SEPARATION ZONES, (2) ALLOWING THE SOLIDS COMPONENTS OF SAIDPULP TO SETTLE INTO A SUBSTANTIALLY COMPACT BED AT THE UPPER END OF SAIDSEPARATION ZONE, (3) ALLOWING SAID COMPACT BED TO DESCEND BY GRAVITYTHROUGH SAID SEPARATION ZONE TO THE LOWER END THEREOF WHILE DIRECTINGTHE PATH OF SAID DESCENT PAST SAID HYDROCARBON COLLECTION ZONES ANDALTERNATELY TOWARDS THE PERIPHERY AND TOWARDS THE AXIS OF SAIDSEPARATION ZONE, WHEREBY THE SOLIDS PASS DOWNWARDLY IN A SINUOUS PATHTHROUGH SAID SEPARATION ZONE IN THE FORM OF A CONTINUOUS COMPACT BEDHAVING THE SHAPE OF A VERTICAL SINUSOIDAL ENVELOPE, (4) REMOVINGESSENTIALLY HYDROCARBON-FREE SOLIDS FROM THE LOWER END OF SAIDSEPARATION ZONE, (5) SIMULTANEOUSLY INTRODUCING AN AQUEOUS LIQUID INTOTHE LOWER END OF SAID SEPARATION ZONE, (6) PASSING SAID AQUEOUS LIQUIDIN A CONTINUOUS STREAM UPWARDLY THROUGH SAID SEPARATION ZONE AND THROUGHSAID HYDROCARBON COLLECTION ZONES IIN A SINUOUS PATH WHICH PASSESTRANSVERSELY ACROSS THE SINUSOIDAL PATH OF DESCENDING COMPACT SOLIDSBED, (7) REMOVING AN AQUEOUS PHASE FROM THE UPPER END OF SAID SEPARATIONZONE, (8) REMOVING A HYDROCARBON PHASE FROM EACH OF SAID HYDROCARBONCOLLECTION ZONES, (9) SEPARATELY PASSING THE HYDROCARBON PHASE REMOVEDFROM EACH OF SAID HYDROCARBON COLLECTION ZONES IN A CONFINED STREAM OUTOF CONTACT WITH THE COMPACT SOLIDS BED AND OUT OF CONTACT WITH SAIDAQUEOUS LIQUID TO A DISCHARGE POINT LOCATED A SUFFICIENT DISTANCE ABOVETHE LIQUID LEVEL IN SAID SEPARATION ZONE THAT SUBSTANTIALLY ONLYHYDROCARBON IS DISCHARGED AT SAID POINT, AND (10) REMOVIING THESO-DISCHARGED HYDROCARBON FROM THE UPPER END OF SAID SEPARATION ZONE. 9.AN APPARTUS FOR SEPARATING A FLUID PULP COMPRISING MINERAL SOLIDS,LIQUID HYDROCARBONS AND WATER WHICH COMPRISES A VERTICALLY ELONGATEDVESSEL CLOSED AT ITS UPPER END AND LOWER END AND HAVING A LIQUID OUTLETOPENING THROUGH ITS WALL ADJACENT TO ITS UPPER END AND A SOLIDS OUTLETOPENING ADJACENT ITS LOWER END, A PULP INLET CONDUIT EXTENDING INTO SAIDVESSEL ADJACENT ITS UPPER END AND TERMINATING WITHIN SAID VESSEL AT APOINT BELOW SAID OUTLET OPENING, A PLURALITY OF PRIMARY BAFFLESPOSITIONED IN SPACED RELATIONSHIP WITHIN SAID VESSELS, EACH OF SAIDPRIMARY BAFFLES TAKING THE FORM OF A HOLLOW CONE WHOSE AXIS COINCIDESWITH THAT OF SAID VESSEL, WHOSE APEX IS DIRECTED UPWARDLY, WHOSE LOWERPERIPHERY HAS A DIAMETER LESS THAN THE INTERNAL DIAMETER OF SAID VESSEL,AND HAVING LOUVRES OPENING THROUGH ITS WALL ADJACENT THE LOWER EDGETHEREOF, A PLURALITY OF SECONDARY BAFFLES POSITIONED IN SPACEDRELATIONSHIP WITHIN SAID VESSEL AND ALTERNATION WITH SAID PRIMARYBAFFLES, EACH OF SAID SECONDARY BAFFLES TAKING THE FORM OF A HOLLOWINVERTED TRUNCATED CONE WHOSE AXIS COINCIDES WITH THAT OF SAID VESSEL,WHOSE UPPER PERIPHERAL EDGE IS IN REGISTER WITH THE WALL OF SAID VESSEL,AND HAVING LOUVRES OPENING THROUGH ITS WALL ADJACENT THE LOWER EDGETHEREOF, A PLURALITY OF FIRST CONDUIT MEANS EACH OF WHICH EXTENDSTHROUGH THE WALL OF ONE OF SAID PRIMARY BAFFLES ADJACENT THE APEXTHEREOF AND TERMINATES AT A POINT ABOVE SAID OUTLET OPENING, A PLURALITYOF SECOND CONDUIT MEANS EACH OF WHICH EXTENDS FROM A POINT ADJACENT ANDBELOW THE UPPER EDGE OF ONE OF SAID SECONDARY BAFFLES AND TERMINATES ATA POINT ABOVE SAID OUTLET OPENING, AND A LIQUID INLET CONDUIT EXTENDINGTHROUGH THE WALL OF SAID VESSEL AND TERMINATING WITHIN SAID VESSEL AT APOINT BELOW THE LOWERMOST OF SAID BAFFLES.